The South West Frontier line of Chennai Suburban Railway is the longest line running South-west from Chennai (Madras) City covering a distance of almost 289 km. Suburban services terminate at Arakkonam and MEMU services run till Villupuram Junction.
Chennai Central - Thiruvallur
edit- This section has 2 dedicated lines for suburban train operations apart from 2 main line for mixed traffic.
- EMUs are operated along 3rd and 4th main lines during peak hours.
- 5th and 6th rail lines are planned.
- 9-car and 12-car EMU are operated in this sector.
Thiruvallur - Arakkonam
edit- This section also has 2 dedicated lines for suburban train operations apart from 2 main line for mixed traffic.
- 9-car, 12-car EMU & MEMU are operated in this sector.
Arakkonam - Katpadi
edit- 8-car MEMU are operated in this sector.
Katpadi - Vellore Cantonment
edit- MEMU service operate between Chennai Beach and Vellore Cantonment via Katpadi.
Vellore Cantonment -Tiruvannamalai- Villupuram
edit- This section has been gauge converted and is being electrified along with passenger services are operating since June. Currently five passenger trains ply over this section